Finding the category that has the most sales in Magento

Sales-by-category.sql

SELECT cat_id, SUM(row_total) as total_sales_by_cat, cv.value FROM (
	SELECT c2.entity_id as cat_id, si.row_total
	FROM catalog_category_product c1
	INNER JOIN catalog_category_entity_varchar c2 ON (c1.category_id = c2.entity_id)
	INNER JOIN catalog_product_entity c3 ON (c1.product_id = c3.entity_id)
	INNER JOIN sales_flat_order_item si ON (si.product_id = c3.entity_id)
	WHERE c2.attribute_id = (SELECT attribute_id FROM eav_attribute WHERE attribute_code = 'name' AND entity_type_id = 3)
	ORDER BY si.created_at DESC
) main
INNER JOIN catalog_category_entity_varchar cv ON (cv.entity_id = cat_id)
GROUP BY cat_id
ORDER BY total_sales_by_cat DESC